Fluoxetine--N-methyl 3-(p-trifluoromethylphenoxy)-3-phenylpropylamine--is described in U.S. Pat. No. 4,018,895, which patent claims a method of treating humans suffering from depression. Pharmaceutical formulations containing fluoxetine are disclosed and claimed in U.S. Pat. No. 4,194,009. The chief pharmacological activity of fluoxetine is as a specific inhibitor of the serotonin neuron pump; i.e., as a serotonin uptake inhibitor. Administration of fluoxetine thus decreases serotonin turnover and release in mammals. In addition, there is a decrease in the output of serotonin neurons. These serotonin neurons have been postulated as being involved in brain functions such as behavior, sleep, sexual activity and hypothalamic control of pituitary hormone release. Inhibition of serotonin uptake as by fluoxetine should enhance processes that are controlled by serotonin neurons. It is reported that fluoxetine pretreatment potentiates the depression of food-reinforced learned behavior by l-tryptophan in pigeons. Fluoxetine is said to promote morphine analgesia according to U.S. Pat. No. 4,035,511.
l-5-Hydroxytryptophan has been reported to cause a fall in blood pressure in conscious rats, in anesthetized dogs pretreated with a monoamine oxidase inhibitor, and in anesthetized cats with or without inhibition of monoamine oxidase or of peripheral decarboxylase. The compound is also said to lower blood pressure on injection directly into the cerebrospinal fluid in dogs. In cats, intracerebral ventrical injection of the same compound lowers blood pressure. The hypotensive effects of l-5-hydroxytryptophan in dogs pretreated with a monoamine oxidase inhibitor are said to be abolished or attenuated by administration of a serotonin antagonist.
Carbidopa and benserazide are used to prevent peripheral decarboxylation of l-dopa in treatment of Parkinsonism.